Prosthetic devices for clinical application are well known. Prosthetic devices which comprise biomaterials, e.g., mammalian tissue of human cadaver or non-human origin, are commonly referred to as “bioprosthetics”. Bioprosthetic devices are frequently used in interventional cardiology, and typically comprise pericardial tissue of human, equine, porcine, ovine, and particularly, bovine origin. Incorporated therein, this exogenous tissue can perform a variety of functions, e.g., as a sewing rim or cuff on a harvested tissue heart valve. Pericardial tissue may also serve as valve leaflets in combination with the structural components of a bioprosthetic heart valve. Several commercially available bioprosthetic devices of this sort which provide excellent hemodynamic performance include, e.g., the TRIFECTA, BIOCOR, and EPIC stented valves and valve systems available from St. Jude Medical, Inc. (St. Paul, Minn.).
While pericardial tissue may be of sufficient tensile strength and durability for use in implantable cardiovascular devices, current methods for harvesting and processing such tissue are limited. Such processing methods include compression based techniques to reduce tissue thickness, e.g., such as described in U.S. Pat. No. 7,141,064. The use of lasers and other mechanical devices to reduce the overall tissue thickness are also described in U.S. 2011/0238167.
Notwithstanding, there remains a need for improved methods for preparing tissue swatches for use in the manufacture of bioprosthetic devices. Specifically, methods which are capable of consistently and efficiently producing tissue swatches of uniform thickness, including uniformly very thin sections of pericardial tissue, as well as tissue swatches of varying thicknesses by design for configuration and incorporation in bioprosthetic cardiovascular devices, are needed.